Rolling oil composition



Patented Nov. 11, 1952 ROLLING OIL COMPOSITION Clayton W. Nichols, Jr.,Mineola, Eldon L. Armstrong, Garden City, and Harold J. Schroeder,Brooklyn, N. Y., assignors to Socony-Vacuum Oil Company, Incorporatedacorporation of New York No Drawing. Application :Iune .2, "1948, SerialNo. 30,734

6 Claims.

The present invention relates to an improved process for rollingnon-ferrous metals and, more particularly, to the elimination orreduction in pick-up in hot-rolling relatively soft aluminum alloys andpure aluminum and the elimination or reduction of staining in therolling of copper alloys, especially brass, through the use of a novelsoluble oil lubricant.

The present invention relates to an improved process for rollingnon-ferrous metals whereby metalsurfaces free of stains and pits areobtained.

In prior art rolling operations on non-ferrous metals, both soluble andnon-soluble roll oils have been used. Non-soluble oils, to which groupthe straight mineral oils and compounded mineral oils belong, weresatisfactory from the standpoint of providing the necessary lubricationbut were deficient in cooling capacity. The lack of cooling capacity isan inherent deficiency of hydrocarbons and fatty oils. It can be assumedfor purposes of fairly accurate approximation that the cooling capacityof hydrocarbons and fatty acid glycerides (fatty oils) is about one-halfthat .of water because the cooling capacity of a cooling medium is adirect function of the specific heat of that cooling medium.

Many attempts have been made in the past to use oil emulsions in orderto take advantage of the lubricating value of their oil content and thecooling value of the water content. Insofar as applicants have been ableto discover, no soluble oil formulation has been offered to thenonferrous metal industry which has satisfied all of the requirements ofrolling mills processing nonferrous metals. The primary deficiency ofthe soluble-oil emulsions which have been tried has been the adverseeffect of the emulsions on the rolled metal surfaces. For example, brasswhen rolled with prior art soluble-oil emulsions containing soap typeemulsifiers, such as sodium or potassium fatty acid soaps, had unsightlystained surfaces.

In hot rolling aluminum, another deficiency of the prior art soluble-oilemulsions was recogniz'ed, to wit: the so-called pick-up. The latterphenomenon is the appearance of nodules or accretions on the surfaces ofthe rolls. The accretions build up and form minute hills which in turnproduce peak um't loads on the new portions of the metal being rolledand the deformation snowballs to a point when the mill must be shut-downand the rolls reground. In addition to considerable loss of time and itsmonetary value, there is an appreciable spoilage of semi-finished metal.

In the early stages of formation the aforesaid accretions can be removedfrom the surfaces of 2 the rolls rather easily. 0n the other hand, whenthrough carelessness or oversight the pick-up is allowed to remain onthe rolls for any appreciable length of time, it is extremely diificultto remove the pick-up without resorting to a-cutting operation. 1

Although several assumptions have been made concerning the compositionof the nodules of pick-up, it has recently been discovered that thematerial consists primarily of aluminum fines with not more than tracesof aluminum oxide, hydroxide, salts and soaps. The use of soluble-oilemulsions containing sodium and/or potassium soaps or sulfonatedmaterials, i. e., conventional type soluble-oil emulsions showed nomarked tendency to prevent the build-up of aluminum particles on workrolls during the hot rolling of aluminum. An experimental solubleoilemulsion .gontaining triethanolamine soap emulsifiers showed someimprovement over the conventional soluble-oil emulsions but was notoutstanding in this respect. Emulsions of the conventional soluble-oiltype having pH values above :10 showed some improvement over similartype emulsions having lower pH values. However, generally, thereappeared to be no simple solution to this problem. Thus, it becamenecessary to attempt .to correlate pick-up and the lubricatingproperties of the soluble-oil emulsions.

Various test machines were used in an attempt to ShQW some correlationbetween lubricating properties of soluble-oil emulsions and pick-uptendencies.- Samples of fresh emulsions and of emulsions whichapparently had reached the end of useful life, in respect to pick-up inthe rolling mill, were used in this test work but, in all cases, no datashowing a significant correlation were obtained. Falex tests were madefor use as a means of estimating probable wear characteristics and the4-Ball machine (described in Army-Navy specifications under the codenumber ,AN-G-IO) was employed to determine the coefficients of frictionbetween steel and aluminum in the presence of the various emulsions.However, no correlation between these properties and pick-up tendencywas readily apparent. These negative results lead to the development ofa test wherein pick-up could be produced at will.

In an attempt to reproduce the actual 'pickup, a Modified 'Timken Testwas developed which. it was hoped, would be helpful in reproducingpick-up. The usual assembly of this equipment was employed with theexception that an aluminum block of soft 28 metal was substituted forthe conventional steel Timken blocks. (28 grade aluminum is the termused by the -industry and in government specifications to designatecommercially-pure metal containing over 99 per cent pure aluminum. Thesmall amount of impurities is chiefly iron and silicon.) The hardenedsteel Timken ring was used and the solubleoil emulsion circulated in theusual manner for this test equipment. The ring was rotated at a speed of400 R. P. M. and a lever arm load of 5 pounds was applied. The durationof the test was one-half hour.

At the completion of the runs with conventional soluble-oil emulsions,it was observed that a greyish tacky deposit covered the steel Timkenring. This material was removed readily by wiping, but on standing itbecame hard and brittle. This close similarity in properties of theexperimental deposit and the cause of the industrial problem lead tointensive examination of both products. This examination, which involvedthe use of both spectrographic and X-ray difiraction techniques, showedthat solid constituent was metallic aluminum. Both the experimentaldeposit and the industrial deposit were the same and consequently themethod for experimentally producing the deposit satisfactorily simulatedactual performance characteristics. Therefore, a measure which in theexperimental procedure eliminated or markedly reduced the amount ofpickup would be effective in actual industrial operations.

All tests carried on samples of used emulsions by the Modified Timkenprocedure described hereinbefore indicated that regardless of length ofservice or concentration, pick-up would occur.

In view of the wide variety of products tested it was manifest thatnumerous factors which might affect pick-up were investigated. Theelimination of such materials as rosin'and petroleum sulfonates wasfound not to improve pick-up characteristics. The addition of variousinorganic salts, organic esters, and metalloorganic compounds providedno complete solution of the problem. Comparison of two soluble-oilemulsions whose anti-wear properties are not comparable established thatthat characteristic is not the controlling factor.

Further investigation showed that when the soluble-oil emulsion was soconstituted that the aluminum was either in solution as a soluble saltor as a dispersed phase of a stable emulsion the tendency to pick-up wasreduced or eliminated. One means whereby the aluminum could be broughtinto solution was the use of an emulsion having a pH of or higher.However, this solution of the problem is not a satisfactory one since itwould be difficult to maintain the pH of a circulating emulsion at orabove pH 10.5 in actual industrial operation.

It was found, however, that an emulsion of soluble-oil in which theemulsifier is of the nonionic type gave satisfactory results. In such anemulsion the particles of metallic aluminum may remain suspended forseveral weeks.

Further investigation of the problem of producing rolled copper or brassfree from stains or substantially so revealed the fact that althoughthere would appear to be no connection between aluminum pick-up and thestaining of brass during cold-rolling nevertheless the use of emulsionsof soluble-oil in which the emulsifier is of the non-ionic type solvedthe problem of coldrolling copper and brass substantially free fromstain. s I

. Accordingly, it is an object of the present in- 4 vention to providean improved method for rolling non-ferrous metals in which a soluble-oilemulsion containing a non-ionic emulsifier is used. It is also an objectof the present invention to provide a soluble oil containing a non-ionicemulsifier and suitable for dilution with water to provide a rollemulsion capable of holding small particles of aluminum in suspensionfor several weeks.

metals is well-known to those skilled in the art.

In general, rolling involves passing a billet of the metal through thebit of two rolls a sufiicient number of times to reduce the billet to asheet of the desired thickness, 1. e., gauge. The amount of reduction ineach pass is dependent upon several factors including composition of themetal being rolled, the temperature of rolling, need for intermediateannealing and the like. However, during the rolling operation, whetherit be a socalled cold-rolling or a hot-rolling, it is necessary to cooland lubricate the working roll or rolls by means of a coolant-lubricant.The coolant-lubricant is usually applied to the working roll as aplurality of streams of liquid in sufficient total quantity to keep theworkin roll from softening and to keep the friction between the workingroll and the metal being rolled to a minimum. In keeping with the spiritof the present invention the coolant-lubricant is an emulsion ofoil-in-water prepared from either fatty oil, i. e., glycerides of fattyacids such as lard oil and others well-known to those skilled in theart, or hydrocarbon oils, such as mineral oils of suitable viscosity,say seconds Saybolt at 100 F. or a combination of fatty and hydrocarbonoils using a non-ionic type emulsifier.

The non-ionic type of emulsifiers are distinctive in that they may beused over -a rather wide pH range and include such materials as glycerololeate, polyglycerol oleate and other similar esters of the long chainaliphatic carboxylic acids, proteins and polyoxyalkylene derivatives ofhexitol anhydride partial esters of long chain aliphatic carboxylicacids. Of the non-ionic type emulsifiers the polyoxyalkylene derivativesof the hexitol anhydride partial esters are preferred.

In addition to the fatty or hydrocarbon oil and emulsifier it isdesirable, and in fact preferred, to use a coupling agent such as butylCarbitol, 2- ethylhexanediol-l,3 or the like.

Illustrative of the novel soluble-oils is the composition A which hasbeen used in the rolling of aluminum and composition B which has beenused in the rolling of brass and other copper alloys. It is to beunderstood that the use of composition A is not limited to the rollingof aluminum alloys nor is the use of composition B limited to therolling of brass or copper alloys. Either composition and analogouscompositions may be used for rolling either aluminum or copper alloys.

Soluble oil 'In general, the composition of the novel soluble-oils willbe within the ranges set forth hereinafter.

Soluble oil Component: Percent by weight 'Glyceride oil or fatty oil to40' Non-ionic emulsifier 0.5 to 15.0 Coupling agent 0.1 to 5.0 Water 0.1to 3.0

Mineral oil (lubricating grade) Balance The soluble-oils having thecomposition set forth hereinbefore may be diluted with water in theproportion of 1 part of oil to 1 to 20 parts of water and satisfactoryroll emulsions obtained.

We claim:

1. A soluble-oil base consisting of an oleaginous lubricant as a majorconstituent, a minor proportion, from about 0.1 weight per cent to about3.0 weight per cent, of Water and an amount, from about 0.5 weight percent to about 15.0 weight per cent, of a, non-ionic emulsifier efiectiveto provide a stable emulsion.

2. A soluble-oil base consisting of a fatty oil, 0 to about 40 weightper cent; a non-ionic emulsifier, about 0.5 to about 15 weight per cent;water, 0.1 to about 3 Weight per cent and the balance mineral oil ofSaybolt Universal viscosity at 100 F. of about 100 seconds.

3. A soluble-oil base as described and set forth in claim 2 in whichabout 0.1 to about 5 weight per cent of a coupling agent is included.

4. A soluble oil base consisting essentially of about 0 to about 5weight per cent of lard oil, about 8.5 to about 9.5 weight per centpolyoxyalkylene derivative of hexitol anhydride partial ester, about 0.5weight per cent 2-ethy1hexanediol-l,3, about 2 weight per cent water andthe balance parafiin oil having a Saybolt Universal viscosity at 100 F.of about 100 seconds.

.5. A soluble-oil base consisting essentially of about 0 to about 40'weight per cent of a glyceride oil, up to about 99 weight per centmineral lubricating oil, a minor proportion from about 0.1 weight percent to about 3.0 weight per cent, of water, and an amount, from about0.5 weight per cent to about 15.0 weight per cent, of polyoxyalkylenederivative of hexitol anhydride partial ester efiective to provide astable emulsion.

6. A soluble-oil base consisting essentially of an oleaginous lubricantas a major constituent, said oleaginous lubricant being selected fromthe group consisting of mineral lubricating oil and a mixture of minerallubricating oil and glyceride oil, a minor proportion, from about 0.1Weight per cent to about 3.0 weight per cent, of water, and an amount,from about 0.5 weight per cent to about 15.0 Weight per cent, of anon-ionic emulsifier effective to provide a stable emulsion.

CLAYTON W. NICHOLS, JR. ELDON L. ARMSTRONG. HAROLD J. SCI-IROEDER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,965,935 Blount et al July 10,1934 1,973,684 Lorig Sept. 11, 1934 2,258,552 Harris Oct. 7, 19412,303,142 Spangler Nov. 24, 1942 2,342,199 Hurtt Feb. 22, 1944 2,382,398Cordero Aug. 14, 1945 2,387,157 Koppenhoefer Oct. 16, 1945 2,404,240MaoLaurin July 16, 1946 2,420,329 Shipp et al. May 13, 1947 2,470,405Leland May 17, 1949 2,470,913 Bjorksten et a1 May 24, 1949

1. A SOLUBLE-OIL BASE CONSISTING OF AN OLEAGINOUS LUBRICANT AS A MAJOR CONSTITUENT, A MINOR PROPORTION, FROM ABOUT 0.1 WEIGHT PER CENT TO ABOUT 3.0 WEIGHT PER CENT, OF WATER AND AN AMOUNT, FROM ABOUT 0.5 WEIGHT PER CENT TO ABOUT 15.0 WEIGHT PER CENT, OF A NON-IONIC EMULSIFIER EFFECTIVE TO PROVIDE A STABLE EMULSION. 